In response to a request for applications (FRA-DC-05-001) for the adaptation or development of language measures that can be used in the characterization of the behavioral phenotypes of language disorders, the goal of our project is to design an instrument that quantifies the use of pragmatics, syntax and semantics in the spontaneous language of children from 2 to 10 years who are suspected of having a language disorder. We will integrate knowledge from developmental psycholinguistics, speech pathology, and psychometrics to design an instrument that moves beyond traditional measures of language ability to assess processes that underlie language acquisition and use associated with different language and developmental disorders in a user-friendly, reliable way that provides continuity of measurement from preschool age to school age children. Building on the framework of naturalistic observations used in the Autism Diagnostic Observation Schedule (ADOS), we will create an instrument with a specific focus on assessing spontaneous language use in a broader population of children with language impairments, including alternate versions in order to measure progress and versions in both English and Spanish. Three phases of development are proposed: 1) Identification of major components of language to be covered by the instrument through consultation with a group of psycholinguists and a group of community "consumers" including speech pathologists, special education teachers and parents, 2) Transcription of 100 and coding of 30 existing ADOS videotapes of stratified samples of two groups of 2 - 10 year-old children from two sites (University of Michigan and Boston University), those with a) developmental delays or language impairments other than autism, and b) those with autism spectrum disorders, to assess what aspects of language are easily observable and codable during existing contexts in the ADOS Modules 2 and 3 and 3) Pilot testing of the new instrument, including additional tasks and a range of new codes, in order to assess the feasibility and psychometric properties of the new measure. Public Health Significance: In the project, a new assessment tool to evaluate the pragmatics, syntax and semantics of children with language impairments will be designed and pilot tested. The tool will provide ways of measuring the severity of children's difficulties in language use that can be employed in studies of the relationship between various neurobiological factors. [unreadable] [unreadable]